Twist axle suspensions are commonly used for the rear suspension of front wheel drive vehicles. As is shown in the prior art illustration of FIG. 1, a twist axle 10 is in combination with first and second trailing arms 12 and 14 that are pivoted by bushings 16 and 18 to a frame or unibody of an automotive vehicle to pivot about coaxial axes 20 and 22, respectively. Wheels 23 and 24 are mounted to hubs 25 disposed at rear ends 26 and 27 of each of the trailing arms 12 and 14. Seats 28 and 29 are provided to support coil springs 30 (only one of which is shown) at the rear ends 26 and 27 of the trailing arms, while dampers 31 (only one of which is shown) are mounted by supports secured proximate the rear ends 26 and 27 of the trailing arms 12 and 14.
Referring now to FIG. 2, since both the road steer and response time of a vehicle are among its critical handling parameters, the twist axle 10 must be designed with an appropriate shear center line location that is defined as a distance “H” between the axles 20 and 22 of the bushings 16 and a shear center line 32. It is desirable that the distance “H” be optimized for specific models of the vehicle. If the specific vehicle platform is used with vehicle models having different ranges of suspension trim, mass and tire parameters, for example, a challenge arises because these differences require different values for the dimension H. Vehicle manufacturers have to either compromise the vehicle by using an axle designed for other models with less than optimal dimensions H, or be forced to manufacture another, different axle with a desired value for H. Resolving this issue is made more complex because it is necessary to maintain critical weld configurations at the junctures between the twist axle 10 and the pair of trailing arms 12 and 14.